I'm a big fan of the Persuasive Technologies Lab at Stanford, and "The Hook" is the best framework and model I've seen derived from their work. The Hook addresses the dynamic development of habit/loyalty/engagement with a brand ... and I mean "dynamic" in the root sense of the term: how a user develops commitment to your offering over time.
I recommend you watch the first 40-minutes of this YouTube lecture by Nir Eyal and maybe go thru these downloadable slides with him at the same time. (Warning for mobile readers: slides are 18mb.)
The model being used is called "The Hook" and it's the brainchild of Nir Eyal, based on work by B.J. Fogg, Dan Ariely and Seth Godin. It starts by pointing out that the favorite diss by VC's -- that your idea is "a vitamin, not a painkiller" -- doesn't explain the success of the largest, most recent "consumer internet" businesses: Facebook, Twitter, Instagram (or Snapchat for that matter), and Pinterest. "Are these iconic companies vitamins ... or painkillers?" Eyal asks at 1:45. He gives the killer answer, starting at 3:00. It will change the way you think about building your business.
What I like most is that at every step of the model, there are tangible ideas to implement, based on solid research from behavioral economics and psychology. It's at least "rational art" if not pure science at this point.
I want to thank Don MacLennan of Bluenose for turning me onto this. He's building an incredible SaaS-based customer insight system and using this model to improve the user experience as users approach, onboard and use the product.
Although Eyal's examples are all internet-based services, the same model can be used to build loyalty with any brand, I believe. For those of you charged with marketing a product that would benefit from repeated use (recurring revs!), I recommend you look closely at this framework.
